<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #d1{
      width: 50px;
      height: 200px;
      background-color: red;
        position: absolute;
        /*控制元素的显示层级,值越大显示越靠前*/

        z-index: 1;
    }
    #d2{
      width: 200px;
      height: 50px;
      background-color: blue;
        position: absolute;
        
    }
    #d3{
        width: 200px;
        height: 200px;
        overflow: scroll;/*设置超出的部分是否显示  hidden隐藏   scroll滚动显示*/
        
    }


  </style>
</head>
<body>
<div id="d1"></div>
<div id="d2"></div>
<div id="d3">
    <img src="../b.jpg" alt="">
    
</div>

</body>
</html>